Handout 1.15
Task B: How to make a slide
(plant cells)
You will need:
Microscope slide
Cover slip
Mounted needle
Distilled water or stain (1% iodine solution). Do not allow iodine solution to come
into contact with skin, as it will stain. For pupils, eye protection is often
recommended even at this dilution because of the slight risk of solution entering
the eye. When working with adults this risk is considered so low as to not require
eye protection.
Small piece of ripped paper towel
Slice of raw onion
What to do
1
Peel off part of the thin membrane from the inside of the onion layer.
2
Place a drop of water or preferably iodine solution on the slide.
3
Carefully place the piece of thin membrane from the onion on the liquid. Be
careful not to trap any air bubbles.
4
Place the edge of a cover slip next to the liquid.
5
Slowly lower the cover slip onto the onion and liquid. Use a mounted needle to
make this easier.
6
Place the ripped edge of a paper towel next to the cover slip so that it draws
out any excess stain and any trapped air.
2 | Strengthening teaching and learning of cells | Notes for participants
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